ANSI C19.4

Description / Abstract: This standard covers enclosures for industrial control apparatus (except those intended for marine auxiliaries and propulsion control apparatus, mine locomotive control apparatus, and railway and railroad locomotion) intended to function on commercial voltages of 750 volts or less, direct current; and 5000 volts or less, alternating current.

In this standard, industrial control apparatus is limited to:

(1) Use with oil or air circuit breakers or contactors with interrupting ratings of 50 000 kV A or less and service voltages up to 5 kV

(2) A combination of properly coordinated fuses and circuit breakers or contactors where interrupting capacity requirement does not exceed ISO 000 kV A at service voltages not exceeding 2500 volts, or where interrupting capacity required does not exceed 250 000 kV A at service voltages greater than 2500 volts and not exceeding 5000 volts